| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.49 |
| Score | 0% | 70% |
The steering wheel of a car is an example of which type of simple machine?
first-class lever |
|
wheel and axle |
|
fixed pulley |
|
block and tackle |
A wheel and axle uses two different diameter wheels mounted to a connecting axle. Force is applied to the larger wheel and large movements of this wheel result in small movements in the smaller wheel. Because a larger movement distance is being translated to a smaller distance, force is increased with a mechanical advantage equal to the ratio of the diameters of the wheels. An example of a wheel and axle is the steering wheel of a car.
Which of the following is not a type of bridge?
block |
|
truss |
|
arch |
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cable |
The six basic bridge forms are beam, truss, arch, cantilever, cable, and suspension.
Drag is a type of:
kinetic energy |
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friction |
|
potential energy |
|
work |
Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.
The advantage of using a third-class lever is that it increases:
the speed of the load |
|
the mechanical advantage of the lever |
|
the distance traveled by the load |
|
the force applied to the load |
A third-class lever is used to increase distance traveled by an object in the same direction as the force applied. The fulcrum is at one end of the lever, the object at the other, and the force is applied between them. This lever does not impart a mechanical advantage as the effort force must be greater than the load but does impart extra speed to the load. Examples of third-class levers are shovels and tweezers.
| 0% | |
| 35% | |
| 8% | |
| 140% |